Master Cylinder

[demian]

I know this has probably been discussed on here before but I tried the search and came up empty. Anyway in order to install the 67-72 dual circuit master cylinder on my 65 c10 is there anything I need besides the master cylinder? I know I will have to plumb for the extra circuit but do I have to do anything else special? Like a lot of other people I plan to go to disc brakes eventually but I need a new master cylinder now and figured I might as well upgrade to the dual circuit. Any help is appreciated.

[Vaughn]

The single circuit type of brakes does not have a proportioning valve. A proportioning valve is important in a disk brake system, less so in a 4 wheel drum system. There are adjustable aftermarket propotioning valves that will work with drum systems and disk/drum systems both. Strictly speaking, you don't need a proportioning valve in an all drum system, but it will help prevent rear lockup in an emergency stop. In a disk/drum system, a proportioning valve is absolutely necessary.

[demian]

Thats exactly what I wanted to know. I wasn't sure if the proportioning valve was necessary in the four wheel drum set up. Thanks for the info.